Community-Based Genetic Testing Reveals Hereditary Risks


Image by Pete Linforth from Pixabay

The Healthy Nevada Project started in 2016 to study the genetic material of thousands of volunteers in Northern Nevada.

Former Governor Brian Sandoval was the first participant, but since then more than 50,000 people around the state have signed up.

Researchers just published a report based on all those samples. They were looking for ways to predict if a patient was at a higher risk of hereditary conditions that can lead to strokes, heart disease and certain kinds of cancer.

“What we found was population genetic screening is an effective tool to identify people who are at risk for a few conditions that we studied,” said Dr. Joseph Grzymski, lead author and principal investigator of the Healthy Nevada Project and professor at Desert Research Institute. 

Those conditions include hereditary breast and ovarian cancer, Lynch syndrome, which puts people at a higher risk for colorectal cancer and endometrial cancer in women, and familial hypercholesterolemia, which increases the risk for high cholesterol and subsequently heart disease.

During normal care, a person might go to a doctor and give family medical history. That doctor may - or may not - tell the patient to get follow up genetic screening for hereditary diseases.

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“In population genetic screening, we basically just say, ‘anybody who wants to join the study, no matter your risk, we will look at you' and then we compare the results of what we found to what the health system finds using those standards of care.”

And the results are startling, Dr. Grzymski said 90 percent of people at risk for those conditions would have been missed following the current standards of care compared with the population-level screening.

The prevalence of the disease found in the study are small only about 1.3 percent of the population or about 300 out of the 27,000 Nevadans screened in the project.

“That may not sound like a lot but 1 percent is significant when you consider that if you have those genetic risks for the three conditions, you have a very, very elevated increase in risk for early death because of developing those cancers or those heart diseases,” he said.

When someone knows they have an elevated risk, Dr. Grzymski said, they can take steps to lower that risk with increased screenings or lifestyle changes.

“If you follow the appropriate prevention mechanisms, you can actually lower the person’s risk almost to background,” he said.

One person who has done that thanks to the Healthy Nevada Project is Jordan Stiteler. She joined the study by simply spitting into a vile and sending it to researchers.

“I found out that I have familial hypercholesterolemia. I have really elevated cholesterol. And I really had no idea,” she said.

Normal cholesterol should be below 199, she said, but when she was tested after being told about her hereditary condition - her cholesterol was 293. She was only 28 years at the time.

Stiteler was surprised when Healthy Nevada Project called her with her genetic test results, but looking back at her family's health history, she realized it wasn't that surprising.

Her great-grandfather died from a heart attack at 40 years old and her father died from a stroke at 45. 

“We had no idea that it was all connected until I joined the Healthy Nevada Project,” she said.

Now, the rest of her family and extended family has been tested for familial hypercholesterolemia and many have it. Since Stiteler and her family know their risks, they can take the necessary steps to protect against heart disease.

Dr. Grzymski noted there are caveats to genetic testing because their knowledge of the mutations that cause those diseases is changing all the time.

He also made a distinction between the work the Healthy Nevada Project is doing and other genetic testing companies.

"For Healthy Nevada Project, the one thing that we’re doing that would be distinguished from a platform like 23 and Me is that we’re sequencing the entire what’s called the exome," he said, "Those are the regions of the human genome that code for the proteins that do the stuff in our body.”

He said many diseases are connected to mistakes in the exome, and since his team maps the entire area, they're more likely to find those mistakes.

When those results are reported to participants, the project encourages them to follow up with a doctor to do more testing, especially for people who have an elevated risk for cancer.

The project also wants people to create a best-care plan with their primary care physician to minimize their known risks.

There may be a time in the far future where genetic testing is part of a regular doctor checkup, Dr. Grzmyski said, but that is years away from becoming a reality.

“The technology is advancing incredibly rapidly," he said, "It is becoming the standard of care diagnosing specific genetic conditions, unknown problems, particularly in pediatrics, definitely in cancer.”

Healthy Nevada Project is currently working on liver disease study and is still recruiting participants, within the limitations of the pandemic.

Dr. Grzmyski said one of the key elements of the research is returning results to participants with hopes they'll improve their own health.

“We’re doing all sorts of research trying to understand genetic risk but we’re providing information back to individuals to help them on their personal health journey,” he said.

Project organizers conducted a pilot study in Southern Nevada with the help of University Medical Center but Dr. Grzmyski said there isn't a way to expand without more funding.

He is hopeful that studies like the one he just completed will help spur funding to expand the project statewide.



Dr. Joseph Grzymski, lead author, principal investigator of the Healthy Nevada Project and professor at Desert Research Institute; Jordan Stiteler, participant, Healthy Nevada Project 

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